Department of Soil Science, Faculty of Agriculture, Kasetsart University, Bangkok 10900, Thailand.
Int J Environ Res Public Health. 2019 Feb 27;16(5):714. doi: 10.3390/ijerph16050714.
Vehicle emissions have been known to cause trace metal contamination in soils. The extent of such contaminations in soils, and of the effects of traffic density and distance from highways on the concentration of trace metals in roadside agricultural soils is largely unknown. This study examined the total concentrations of common trace metals (Cd, Co, Cr, Cu, Ni, Pb, V, and Zn) in roadside agricultural soils from Thailand with diverse traffic densities (approximately 30⁻200 million vehicles/kilometer/year), roadside distances (0, 10, 20, 50, and 100 m from the road edge), and crops (rice, maize, and sugarcane). Cadmium, Cu, Pb, and Zn concentrations significantly decreased with increasing distance away from the roads ( < 0.05). However, the concentrations of these metals were not correlated with traffic density, probably due to extensive road maintenance and expansion. The contamination factor demonstrated that the road edge soils were moderately- to highly-polluted with Cd, Cu, Pb, and Zn. The safest distance to minimize metal pollution for agricultural production is proposed to be greater than 10 m away from the road edge.
车辆排放物已被证实会导致土壤中的痕量金属污染。然而，土壤中此类污染的程度，以及交通密度和距高速公路距离对路边农业土壤中痕量金属浓度的影响在很大程度上尚未可知。本研究检测了泰国不同交通密度（约 3000 万至 2 亿辆/公里/年）、路边距离（距路边 0、10、20、50 和 100 米）和作物（水稻、玉米和甘蔗）的路边农业土壤中常见痕量金属（Cd、Co、Cr、Cu、Ni、Pb、V 和 Zn）的总浓度。距道路越远，Cd、Cu、Pb 和 Zn 的浓度越低（<0.05）。然而，这些金属的浓度与交通密度没有相关性，这可能是由于道路的广泛维护和扩建。污染因子表明，路边土壤受到 Cd、Cu、Pb 和 Zn 的中度至高度污染。建议距离道路边缘大于 10 米，以最大程度减少金属污染对农业生产的影响。
